1. Field of the Invention
Aspects of the present invention relate to a digital broadcasting transmission apparatus which inserts information for receiver demodulation in a transmission signal, and an inserting method thereof, and more particularly, to a digital broadcasting transmission apparatus which enables a receiver to obtain precise information for demodulation and to provide an improved reception performance, and an inserting method thereof.
2. Description of the Related Art
FIG. 1 is a block diagram of a general digital broadcasting transmission apparatus, and FIG. 2 is a view illustrating a general field sync signal.
The general digital broadcasting transmission apparatus shown in FIG. 1 is an existing standard 8-level vestigial sideband (VSB) transmission apparatus and includes a randomizer 10, a Reed-Solomon (RS) encoder 12, an interleaver 14, a trellis encoder 16, a multiplexer 18, a pilot inserter 20, a modulator 22, and a radio frequency (RF) transformer 24.
A transmission process of the general digital broadcasting transmission apparatus having the above-described structure will now be described briefly. The randomizer 10 randomizes a transport stream (TS). The RS encoder 12 adds parity bits to the TS to correct an error. The interleaver 14 interleaves the TS, and the trellis encoder 16 trellis encodes the interleaved TS.
The multiplexer 18 inserts a field sync signal and a segment sync signal into the TS having undergone error correction encoding to multiplex the TS. The pilot inserter 20 inserts a pilot signal into the TS, the modulator 22 performs VSB modulation on the TS, and the RF transformer 24 transforms the modulated signal into an RF signal, amplifies the RF signal, and transmits the RF signal through a channel assigned a predetermined band.
As shown in FIG. 1, the multiplexer 18 of the general digital broadcasting transmission apparatus inserts the field sync signal and the segment sync signal into the TS to perform multiplexing. Here, the field sync signal and the segment sync signal are used by a reception apparatus to perform synchronization and equalization and compares data that are well known between the general digital broadcasting transmission apparatus and the reception apparatus. The field sync signal is shown in FIG. 2.
The field sync signal is regularly repeated at an interval of 24.2 ms and includes one complete segment starting from the segment sync signal. Each symbol is expressed with 2 levels, and the field sync signal includes 832 symbols.
As shown in FIG. 2, the field sync signal having 832 symbols includes four segment sync signal symbols, a PN 511, three PN63 pseudo random sequences, a VSB mode, and a reserved area.
Here, the last 12 symbols of the reserved area are in a pre-code area reserved to transmit the last 12 symbols of a previous field, and 10 symbols of a front end of the pre-code area are in an extension segment area providing information about a turbo coding used in the transmission apparatus. Generally, approximately 82 symbols of 104 symbols of the reserved area except for the last 12 symbols of the pre-code area and the 10 symbols of the extension segment area may be used to provide information about a technology used by the transmission apparatus to improve a reception performance with the approval of the Advanced Television Systems Committee (ATSC).
It is important that the transmission apparatus safely transmits information about a technology used in the transmission apparatus to improve reception performance so that the receiver can provide a good reception performance as intended by the transmission apparatus.
Therefore, a method is required, which inserts information about a technology used in the transmission apparatus to improve a reception performance into segment sync signals and field sync signals used as reference signals during the performance of equalization in the receiver so that the receiver can readily utilize the received information.